*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}
.container{
    width: 270px;
    height: 400px;
    background-color: #f6e58d;
    font-family: 'Shadows Into Light', cursive;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    border-radius: 10px;
    box-shadow: 15px 15px 15px rgb(88, 55, 55,.5);
    overflow: hidden;
    position: relative;
}
.container h2{
    letter-spacing: 5px;
    font-size: 35px;
    color: #fff;
    text-shadow: 0 0 5px rgba(127, 54, 54,.5), 0 0 5px rgba(127, 54, 54,.5);
}
.container .btn{
    display: block;
    border: none;
    outline: none;
    width: 200px;
    height: 40px;
    border-bottom: 2px solid black;
    background: none;
}
.container form{
    width: 270px;
    height: 200px;
    display: flex;
    justify-content: space-around;
    align-items: center;
    flex-direction: column;
    background: none;
    color: #fff;
}
.container form .sub{
    width: 200px;
    height: 40px;
    outline: none;
    border-radius: 15px;
    color: blueviolet;
    letter-spacing: 3px;
    background: none;
    border: solid 1px #fff;
}
/* 设置鼠标进去的样式 */
.container .in{
    position: absolute;
    width: 0;
    height: 0;
    top: 0;
    left: 0;
    display: block;
    transform: translate(-50%,-50%);
    border-radius: 50%;
    background: #25CCF7;
    animation: in .5s ease-out forwards;
}
/* 设置鼠标离开的样式 */
.container .out{
    position: absolute;
    width: 1200px;
    height: 1200px;
    top: 0;
    left: 0;
    display: block;
    transform: translate(-50%,-50%);
    border-radius: 50%;
    background: #25CCF7;
    animation: out .5s ease-out forwards;
}

/* 设置鼠标进去的动画 */
@keyframes in {
    0%{
        width: 0;
        height: 0;
    }
    100%{
        width: 1200px;
        height: 1200px;
    }
}

/* 设置鼠标离开的动画 */
@keyframes out {
    0%{
        width: 1200px;
        height: 1200px;
    }
    100%{
        width: 0;
        height: 0;
    }
}
